Electronics Forum | Mon Jan 22 22:37:27 EST 2001 | davef
50 ppm oxygen was on half joints reflowed in air. 3d Human factors PCB pad cleanliness: Handling of bare board pads creates excessive voiding. Print rejection: Cleaning of OSP pads with acetone or isopropanol increases voiding.
Electronics Forum | Fri Aug 23 20:11:34 EDT 2002 | jersbo
thats the problem with numbers... how accurate are they anyway? Can someone tell me how to collect data and assure me that its not someones biased opinion?
Electronics Forum | Tue Sep 03 14:18:49 EDT 2002 | dragonslayr
Jersbo- I will refer you to the late, Great Mark Twain, who once wrote: "There are 3 kinds of lies in this world - Lies Damn Lies and Statistics"
Electronics Forum | Wed Aug 21 17:50:05 EDT 2002 | davef
First, it�s GREAT that your defect rate of 282 is very close to your Boss� goal of 50 ppm. Second, your Cpk and your ppm numbers don�t tie out with our expectations. You say Cpk for: * mounter is 1.0 and �your mounting is 83ppm�. * printing is 1.33
Electronics Forum | Wed Aug 21 18:11:47 EDT 2002 | dragonslayr
..and the choir is humming in 5 part harmonies. Personnally, I never gave much truck to Cpk stuff. Seems to be a high falutin way of showing the lowerlings that academics can manipulate numbers. Dazzle 'em with brilliance or baffle 'em with bull puke
Electronics Forum | Wed Sep 04 14:14:55 EDT 2002 | melo_guy
I like that "Lies, dam lies and statistics." thats a riot, only because its SO TRUE. Ill remember that i'm sure ill be able to use it sometime. My company does a lot of those graphs and charts that all relate to things that make no sense. I'm in c
Electronics Forum | Wed Jul 07 13:37:56 EDT 2004 | mark
Not sure if this helps but found this site that outlines % of N2 against O2 ppm levels. You need 99.99% N2 purity for http://www.tkb-4u.com/articles/consumables/whatisnitrogen/whatisnitrogen.php Most customers we have worked with in the past run an
Electronics Forum | Tue Sep 18 10:22:22 EDT 2001 | jschake
Paste Flux / Reflow: Our experiments indicated that the combination of no-clean solder paste and air forced convection reflow produced the fewest tombstone defects, followed by water-soluble paste reflowed in air, and most tombstones occurring with
Electronics Forum | Tue Feb 07 09:49:10 EST 2006 | George
Hello everybody, I have been asked to establish a way to improve our wave solder process. I wonder where I should start. We collect data by inspecting our PCB's visually. What's the best way to report data? Ocurrence of defects in total among all
Electronics Forum | Tue Jun 26 16:07:12 EDT 2018 | eduszapata29
Minami vacuum reflow is easy to maintain air tightness, and oxygen can be reduced to 50ppm or less by filling N2 gas. And generation of oxide film can be suppressed, and production in low oxygen environment is possible. In addition to the air tightne
